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![](https://rs.olm.vn/images/avt/0.png?1311)
2KMnO4-to>K2MnO4+MnO2+O2
0,3-----------------0,15-----0,15------0,15 mol
n KMnO4=\(\dfrac{47,4}{158}\)=0,3 mol
=>mcr=0,15.197.0,15.87=42,6g
=>VO2=0,15.22,4=3,36l
b) 4P+5O2-to>2P2O5
0,1--------------0,05
nP=\(\dfrac{3,1}{31}\)=0,1 mol
->O2 dư
=>m P2O5=0,05.142=7,1g
mKMnO4 = 47,4/158 = 0,3 (mol)
PTHH: 2KMnO4 -> (t°) K2MnO4 + MnO2 + O2
Mol: 0,3 ---> 0,15 ---> 0,15 ---> 0,15
m = 0,15 . 197 + 0,15 . 87 = 85,2 (g)
V = VO2 = 0,15 . 22,4 = 3,36 (l)
nP = 3,1/31 = 0,1 (mol)
PTHH: 4P + 5O2 -> (t°) 2P2O5
LTL: 0,1/4 < 0,15/5 => O2 dư
nP2O5 = 0,1/2 = 0,05 (mol)
mP2O5 = 0,05 . 142 = 7,1 (g)
![](https://rs.olm.vn/images/avt/0.png?1311)
a, \(n_{Na}=\dfrac{3,45}{23}=0,15\left(mol\right)\)
PT: \(2Na+2H_2O\rightarrow2NaOH+H_2\)
Theo PT: \(n_{NaOH}=n_{Na}=0,15\left(mol\right)\Rightarrow C_{M_{NaOH}}=\dfrac{0,15}{0,2}=0,75\left(M\right)\)
b, \(n_{H_2}=\dfrac{1}{2}n_{Na}=0,075\left(mol\right)\)
\(n_{O_2}=\dfrac{0,96}{32}=0,03\left(mol\right)\)
PT: \(2H_2+O_2\underrightarrow{t^o}2H_2O\)
Xét tỉ lệ: \(\dfrac{0,075}{2}>\dfrac{0,03}{1}\), ta được H2 dư.
Theo PT: \(n_{H_2O}=2n_{O_2}=0,06\left(mol\right)\Rightarrow m_{H_2O}=0,06.18=1,08\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_P=\dfrac{6,2}{31}=0,2\left(mol\right)\\ n_{O_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\\ PTHH:4P+5O_2\underrightarrow{t^o}2P_2O_5\\ LTL:\dfrac{0,2}{4}< \dfrac{0,4}{5}\Rightarrow O_2dư\)
\(n_{O_2\left(pư\right)}=\dfrac{5}{4}n_P=\dfrac{5}{4}.0,2=0,25\left(mol\right)\\ n_{O_2\left(dư\right)}=0,4-0,25=0,15\left(mol\right)\)
\(n_{P_2O_5\left(lt\right)}=\dfrac{1}{2}n_P=\dfrac{1}{2}.0,2=0,1\left(mol\right)\\ m_{P_2O_5\left(lt\right)}=0,1.142=14,2\left(g\right)\\ m_{P_2O_5\left(tt\right)}=0,1.142.80\%=11,36\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_P=\dfrac{m_P}{M_P}=\dfrac{4,65}{31}=0,15mol\)
\(4P+5O_2\rightarrow\left(t^o\right)2P_2O_5\)
0,15 0,075 ( mol )
\(m_{P_2O_5}=n_{P_2O_5}.M_{P_2O_5}=0,075.142=10,65g\)
\(n_{H_2O}=\dfrac{m_{H_2O}}{M_{H_2O}}=\dfrac{18}{18}=1mol\)
\(P_2O_5+3H_2O\rightarrow2H_3PO_4\)
0,075 < 1 ( mol )
0,075 0,15 ( mol )
\(m_{H_3PO_4}=n_{H_3PO_4}.M_{H_3PO_4}=0,15.98=14,7g\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 4P + 5O2 --to--> 2P2O5
b) \(n_P=\dfrac{24,8}{31}=0,8\left(mol\right)\)
PTHH: 4P + 5O2 --to--> 2P2O5
0,8--------------->0,4
=> mP2O5 = 0,4.142 = 56,8 (g)
c)
PTHH: P2O5 + 3H2O --> 2H3PO4
0,4--------------->0,8
=> mH3PO4 = 0,8.98 = 78,4 (g)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(a,PTHH:4P+5O_2\xrightarrow{t^o}2P_2O_5\\ b,n_P=\dfrac{6,2}{31}=0,2(mol)\\ \Rightarrow n_{O_2}=\dfrac{5}{4}n_P=0,25(mol)\\ \Rightarrow V_{O_2(đktc)}=0,25.22,4=5,6(l)\\ c,n_{P_2O_5}=\dfrac{1}{2}n_P=0,1(mol)\\ \Rightarrow m_{P_2O_5}=0,1.142=14,2(g)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Ta có: \(n_{C_4H_{10}}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
PT: \(2C_4H_{10}+13O_2\underrightarrow{t^o}8CO_2+10H_2O\)
a, Theo PT: \(n_{O_2}=\dfrac{13}{2}n_{C_4H_{10}}=1,3\left(mol\right)\)
\(\Rightarrow V_{O_2}=1,3.22,4=29,12\left(l\right)\)
b, Theo PT: \(n_{CO_2}=4n_{C_4H_{10}}=0,8\left(mol\right)\)
\(\Rightarrow m_{CO_2}=0,8.44=35,2\left(g\right)\)
c, PT: \(CO_2+2KOH\rightarrow K_2CO_3+H_2O\)
Theo PT: \(n_{K_2CO_3}=n_{CO_2}=0,8\left(mol\right)\)
\(\Rightarrow m_{K_2CO_3}=0,8.138=110,4\left(g\right)\)
2C4H10 + 13O2 = nhiệt độ => 8CO2 + 10H2O
nC4H10= \(\dfrac{4,48}{22,4}\)= 0,2 (mol)
=> nCO2= 5.nC4H10= 5.0,2 = 1 (mol)
=> mCO2= 1.44=44 (g)
nO2=\(\dfrac{13}{2.n_{C4H10}}\)= \(\dfrac{13}{2}\).0,2= 1,3 (mol)
=> VO2= 1,3 . 22,4= 29,12 (l)
\(a) n_P = \dfrac{12,4}{31} = 0,4(mol)\\ 4P + 5O_2 \xrightarrow{t^o} 2P_2O_5\\ n_{P_2O_5} = \dfrac{1}{2}n_P = 0,2(mol)\\ \Rightarrow m_{P_2O_5} = 0,2.142 = 28,4(gam)\\ b) P_2O_5 + 3H_2O \to 2H_3PO_4\\ n_{H_3PO_4} = 2n_{P_2O_5} = 0,4(mol)\\ m_{dd} = 28,4 + 200 = 228,4(gam)\\ \Rightarrow C\%_{H_3PO_4} = \dfrac{0,4.98}{228,4}.100\% = 17,16\%\)
nP = 12.4/31 = 0.4 (mol)
4P + 5O2 -t0-> 2P2O5
0.4.......................0.2
mP2O5 = 0.2 * 142 = 28.4 (g)
P2O5 + 3H2O => 2H3PO4
0.2.............................0.4
mH3PO4 = 0.4 * 98 = 39.2 (g)
mddH3PO4 = 28.4 + 200 = 228.4 (g)
C% H3PO4 = 39.2/228.4 * 100% = 17.16%